George Zimmerman sits Seminole circuit court on on Wednesday. He is accused in the fatal shooting of Trayvon Martin. / Joe Burbank, AP

by Yamiche Alcindor, USA TODAY

by Yamiche Alcindor, USA TODAY

SANFORD, Fla. - The jurors and alternates selected to hear the trial of the man accused of killing Trayvon Martin will be sequestered, a judge ruled Thursday afternoon.

Judge Debra Nelson announced during the jury selection that the jurors will be sequestered for George Zimmerman's second-degree murder trial, which is expected to last two to four weeks.

During the first four days of jury selection, lawyers had been asking potential jurors whether being sequestered would be a hardship on them. Most said they could serve on the jury but cited family, work and school responsibilities as concerns.

Zimmerman is pleading not guilty to second-degree murder. He claims he shot Trayvon Martin, 17, in self-defense.

Shortly after the decision, Zimmerman's attorney, Mark O'Mara, asked one potential juror whether she could cope with being sequestered.

"Will I have Internet access to do my quizzes online?" the middle-aged woman, who is a student, asked. "I have homework."

Later, she said she could handle being sequestered because her school probably has procedures in places for such situations. She added that she has a young son who is spending the summer in Ohio with his grandparents, a husband who works and a daughter who lives on her own.

Since Monday, 33 potential jurors have been questioned by lawyers in the first phase of questioning.

This stage, called the "pre-publicity voir dire" is aimed at learned how much each person knows about the case and how much they have discussed the case either online or with others.

As of Wednesday, 85 potential jurors had been dismissed, court officials said.

The trial requires six jurors and four alternates.

"Sequestration of a jury is rare but it is crucial in a case that is high-profile such as this," said Elizabeth Parker, a Florida criminal defense attorney and former assistant state prosecutor. "This was an important ruling for both the state and defense to protect the integrity of the criminal justice process, to protect the privacy of the jurors and to ensure that the jurors decide the case based upon information that they learned during the trial."

Parker said it is crucial that a juror not decide a case based upon information received from an outside source such as the internet, television or newspapers.

Sequestration also reduces the pressure on jurors to vote a certain way, and it helps prevent harassment, threats, or actual violence from non-jurors who want to influence the outcome of the case, Parker said.

As part of the sequestration, Judge Nelson will likely instruct the jurors that they are not to view, listen or talk to anyone about the facts of the case, Parker said.